Process for producing 16beta-alkyl and 16beta-alkyl steroids of the pregnane series



United States Patent 3,345,387 PROCESS FOR PRODUCING 16B-ALKYL AND 16a-ALKYL STEROIDS OF THE PREGNANE SERIES David Taub, Metuchen, Norman L. Wendler, Summit, and Harry L. Slates, Florham Park, NJ., assignors to Merck & Co., Inc., Rahway, N.J., a corporation of New Jersey No Drawing. Continuation of application Ser. No. 11,983, Mar. 1, 1960, which is a division of application Ser. No. 722,390, Mar. 19, 1958. This application May 25, 1964, Ser. No. 370,106 g 2 Claims. (Cl. 260397.45)

nit

where R is alkyl, R is hydrogen or acyl, R" is hydroxy or oxygen, and X is hydrogen or halogen. The broken line between carbon atoms 1 and 2 indicates that a double bond may be present in this position.

The 16fi-alkyl steroids produced in accordance with the present invention possess extremely high anti-flammatory activity, considerably greater than that of the parent steroids, and are especially effective for the treatment of arthritis and related diseases'since they can be administered for their cortisone-like action in extremely low dosage thereby minimizing undesired side efliects. The activity of 16 beta-alkyl steroids is especially novel as all previous group substitution modifications of cortical steroids which have resulted in increased anti-inflammatory activity have involved introduction of alpha-substituents.

In preparing our novel chemical compounds, the starting material utilized may be a 3-subs'tituted-1l-oxygenated-16-pregnene 20 one or 3 substituted-11- oxygenated 16 allopregnene 2-0 one which may be identified by the following structural formula wherein X is hydrogen or halogen, Y is alpha or beta hydrogen, Z is oxygen, dioxolane, alpha or beta a'cyloxy 9 3,345,387 Patented Oct. 3, 1967 or hydroxy, and R" is hydroxy or oxygen as above, with or without a double bond at the 5(6)-position.

In a preferred embodiment of our invention, 30cacetoxy-l6-pregnene-11,20-diene which is represented by the following formula:

is utilized as the starting material. However, it is clear to those skilled in the art that other starting materials, such as those described above, may be similarly converted to the desired end products.

It has been found that 3a-acetoxy 16 pregnene 11, 20-dione may be caused to react with diazoalkanes, such as diazomethane and diazoethane to form 3a-acetoxy- 16a,17a-alkyleneazopregnane-11,20-dione which has the following structural formula:

where R is hydrogen or alkyl.

Upon heating 3a-acetoxy l6a,l6a-alkyleneazopregname-11,20-dione, there is formed primarily 3a-acetoxy- 16-alkyl-16-pregnene-11,2-0 dione which may be represented by the following formula:

to AGO-O3 wherein R is alkyl as above.

Heating 30: acetoxy-16u-17a-a1kyIeneazopregnane-1l, 20-dione also results in the formation of a small quantity of each of the two corresponding isomeric forms namely, the cyclopropane, 3-acetoxy-l6a,l7a-alkylenepregnane- 11,20-dione, which has the following structural formula:

wherein R'" is hydrogen or alkyl and exocyclicolefin, 3-

q '3 acetoxy-l6-alkylenepregnane-11,20-dione, which may be represented by the formula:

l Ac0-- where R is hydrogen or alkyl as above.

Treatment of the above isomeric form, namely the 3- acetoxy-l6-alkylenepregnane-11,20-dione with an alkali hydroxide yields 16ot-alkyl-3 x-hydroxy-l6-pregnene-l1,20- dione which has the formula:

wherein R is alkyl.

Oxidation of 3a-acetoxy-16-alkyl-16-pregnene-l 1,20- dione, the major isomer obtained above, with an oxidizing agent such as hydrogen peroxide in the presence of sodium hydroxide or peracids such as peroxytrifluoroacetic acid results in the formation of 16fl-alkyl-l 6a,l7a-epoxy-3ahydroxypregnane-l1,20-dione which has the structural formula:

-----o W H0-C wherein R is as above.

Upon treatment of 16 8-alkyl-16a,l7wepoxy-3a-hydroxypregnane-11,20-dione with a strong acid such as perchloric acid there is formed an olefin mixture of 16- alkyl-3a,17u-dihydroxy-15-pregnene-l1,20-dione and 16- a1kylene-3a,17a-dihydroxy-pregnane 11,20 dione which may be represented as follows tg j "-011 0 TGHR'" I wherein R is hydrogen or alkyl and R is as above.

and

Treatment of the mixture of 16-alkyl-3a,17u-dihydroxy- IS-pregnene 11,20 dione and 16-a1kylene-3a,17u-dihydroxyprcgnane-l1,20-dione successively with lithium aluminum hydride and sodium mctaperiodate results in a mixture of the endocyclic l-6-alkyl-3a,llfl-dihydroxy-lS- etiocholene-l7-one and the exocyclic, l6-alkylene-3a,llfldihydroxyetiocholane-17-one having the structural forwherein R' is hydrogen or alkyl and R is alkyl as above.

Upon treatment of 16fl-alkyl-16a,17u-epoxy-3a-hydroxypregnane-l1,210-dione with hydrogen bromide in acetic acid there is formed 3a-acetoxy-16-alkylene-17ozhydroxy-pregnane-l1,20-dione, uncontaminated with the 15-pregnene isomer. There is also produced 3u-acetoxy- 16-alky1-15a-bromo-16-pregnene-l1,20-di0ne which may be represented by the following formula and wherein R is alkyl. The 3a-acetoxy-16-alkyl-15u-bromo- 16-pregnene-11,20-dione thus produced is an important intermediate in the preparation of other active steroids.

The 30; acetoxy-l6-alkyl-15a-bromo-16-pregnene-l1, 20-dione may be reacted with pyridine to form Bot-acetoxy-16-alkyl-14,16-pregnadiene-11,20-dione which has the formula 16/3-a1kyl-3 a,17a-dihydroxypregnane 11,20 dione which maybe represented as follows I -OH L"OH TR I and I HO-- HO wherein R is as above.

Alternatively, hydrogenation of 16,8-alkyl-l6u,17ocepoxy-3a-hydroxypregnane-11,20-dione under acidic conditions produces directly the above mixture of 16u-a1ky1- 3a,17a-dihydroXypregnane-11,20-dione and 16B-a1ky1-3a, 17a-dihydroxypregnane-11,20-dione.

Similarly hydrogenation of the pure 16-a1kylene-3 0:,1705- dihydroxypregnane-l1,20-dione resulted in the mixture of 16a-alkyl-3a,17a-dihydroxypregnane 11,20 dione and l6fl-alkyl-3a,17a-dihydroxypregnane-11,20-dione.

At this stage, the mixture may be separated into its components by chromatography or fractional crystallization or other means. As hereinafter described the mixture can be processed in the same manner as either of the two components.

Bromination of the above epimeric mixture of 16aa1ky1-3 a,17a-dihydroxypregnane-1 1,20-dione and 16,3-alkyl-3oc,17a-dihydroxypregnane-11,20-dione results in the' formation of an epimeric mixture of 16a-alkyl-21-bromo- 3u,17a-dihydroxypregnane-11,20-dione and 16 8-alkyl-2lbromo-3u,17a-dihydroxypregnane-11,20-dione which may be represented as follows CHgBr HO I m H003 ma a wherein R is as above.

The above epimeric mixture may be separated by chromatography or crystallization at this stage or carried further.

Reaction of a mixture of 16a-alkyl-3u,17u,21-trihydroxypregnane-l1,20-dione 21-acetate and 16B-alky1-3a, 170:,21-trihydroxypregnane-11,20-dione 21-acetate with an oxidizing agent such as .N-bromosuccinimide or chro- 'mic acid results in the formation of a mixture of IGoc-al- 6 kyl-17a21-dihydroxypregnane 3,11,20 trione ZI-acetate and 16,6-alkyl-17u,21-dihydroxypregnane 3,11,20 trione 21-acetate which have the following structural formulae CH OAe C=O ---0H I and O- 0 wherein R is as above.

The mixture of 16a -alkyl-17a,21-dihydroxypregnane- 3,11,20-trione ZI-acetate and lfi-alkyl-l7u,2l-dihydroxypregnane-3,11,20-trione 21-acetate can be separated by chromatographic procedures.

The 16/3 alkyl ;,21 dihydroxypregnane-3,l1,20- trione 21-acetate is reacted With bromine to form 16,8- alkyl-4-bromo 170:,21 dihydroxypregnane-3,11,20-trione 21-acetate which has the following structural formula CHzOAc wherein R is alkyl.

The 16fl-alkyl-4-bromo 171:,21 dihydroxypregnane-il, 11,20-trione 21-acetate obtained above is then reacted with a slurry of semicarbazide hydrochloride and sodium bicarbonate to form the 3-semicarbazone of 16p-alkyl-17a, 21-dihydroxy-4-pregnene-3,11,20-trione 21-acetate which may be represented by the following structural formula o I ---oH IF I NH; 0 o NHN=L/ no QU wherein R is as above.

The above compound may also be named 16fl-alkylcortisone acetate, one of our active end products which possessess effective anti-inflammatory activity.

It has been found that the 16B-alkyl-17a,2l-dihydroxy- 4-pregnene-3,11,20-trione 2l-acetate may be converted to the corresponding 21-01, namely, 16[3-alkyl-17a,21-dihydroxy-4-pregnene-3,l1,20-trione, by reaction with potassium bicarbonate in aqueous methanol. The latter compound is then reacted with semicarbazide hydrochloride in the presence of dimethylforrnarnide to form the 3,20-disemicarbazone of 16B-alkyl-17a,21-dihydroXy-4-pregnene- 3,11,20-trione which has the following structural formula (3112011 (3=NNHC ONH:

wherein R is alky as above.

Reduction of the 3,20-disernicarbazone of 16,8-alkyl- 17a,21-dihydroxy 4 pregnene 3,11,20-trione with sodium boronhydride produces the 3,20-disernicarbazone of 16p-alkyl-11B,17a,21 trihydroxy 4 pregnene-3,2O- dione, which has the following formula:

wherein R is as above.

The 3,20-disemicarbazone of 16,8-a-lkyl-11fl,l7oc,21-trihydroxy-4-pregnene-3,20-dione is reacted with pyruvic acid in aqueous acetic acid to remove the semicarbazone groups at the 3 and 20-positions to form 16fi-alkyl-11B, 17a,21-trihydroxy-4-pregnene-3,20-dione whichmay be chemically represented as follows:

CH2OH .rQU

wherein R is as above. The above compound which may be called 16fl-alkyl hydrocorti sone has been found to exhibit marked and effective activity in the treatment of arthritis.

Acetylation of 16/3 alkyl 11fi,17a,21-trihydroxy-4- pregnene-3,20-dine at the 21-p'osition is accomplished by reacting this latter compound with acetic anhydride in the presence of pyridine to form 16B-alkyl-11B,17x,21- tn'hydroXy-4-pregnene-3,20 -dione 21-acetate which may be represented as follows:

CHZOAG wherein R is as above.

Other 2l-acylates may be prepared by reacting the 21-alcohol with the appropriate acyl anhydrides.

By reacting l6fi-alkyl-11p,l7a,'21-trihydr0Xy-44preg 1 none-3,20-dione 2l-acetate with methanesulfonyl chloride in dimethylformamide there is formed 16,6-alkyl- 1706,21 dihydroxy 4,9(11)pregnadiene-3,20-dione 21- acetate of the following structural formula CHzOAc wherein R is as above.

Reacting the latter compound with N-brotmo-succinimide forms 16fi-alkyl-9a-bro-mo-l 1/3,l7a,2l-trihydroxy- 4-pregnene-3,20-dione 2l-acetate represented by the formula wherein R is as above.

Reacting the latter compound with sodium methoxide produces 165 alkyl-9fi-11,8-epoXy-17oa21-dihydroxy-4- pregnene-3,20-dione having the formula wherein R is as above.

The latter compound is acetylated with acetic anhydride in pyridine and then allowed to react with hydrogen fluoride, to form 16fi-alkyl-9u-fluoro-11fl,17a,21-trihydroXy-4-pregene-3,20-dione 21-acetate of the following structural formula CHgOAc and 16B-alkyl 9oz fluoro-17a,21-dihydroxy-1l-oxygenated-1,4-pregnadiene-3,20-dione and the corresponding 21-acy'1ates can be prepared by reacting respectively 165- alkyl-l7a,2l-dihydroxy-1l-oxygenated pregnane 3,20- dione 21-acetate and 16,8 alkyl 9.x fluoro-17u,21- dihydroxy-l l-oxygenated pregnane-3,20-dione 21-acetate with bromine to form the corresponding 16,8-alkyl-2,4-dibromo-17a,2l-dil1ydroXy-1l-oxygenated pregnane 3, 20-di0ne 21-acetate which has the following structural formula:

E. g m e wherein R is as above and X is hydrogen or fluorine and R" is hydroxy or oxygen.

Treatment of these species with dimethyl aniline in dimethylformamide results in the desired 16f3-alkyl-17u, 2l-dihydroXy-1l-oxygenated 1,4 pregnadiene-3,20-dione 21-acetate and 16-fl-alkyl-9a-fluoro-17a,21-dihydroXyll-oxygenated 1,4 pregnadiene-3,20-dione 21-acetate which may be represented graphically as follows:

wherein R, R" and X are as above. The species represented by the above formula are highly potent anti-inflammatory agents.

The 21-acetate esters of these compounds can be hydrolyzed to the corresponding alcohols, 1 6B-alky1-17a,21- dihydroxy-ll-oxygenated-1,4-pregnadiene-3,20dione and 16 3-alkyl-9a-flu0ro 17.1,21 dihydroxy-ll-oxygenated- 1,4-pregnadiene-3,2--dione represented by the following structural formula CHnOH through diatomaceous earth, concentrated to about 100 1 0 EXAMPLE 1 Preparation of 3u-acetoxy-16ot,1 7 a-methyleneazo-pregnane l 1 ,ZO-diowe In a 500 ml. 3-neck flask equipped with condenser, dropping funnel and nitrogen inlet were placed 20 g. of potassium hydroxide in 9-0 ml. of water, ml. of methanol and 1 00 ml. of ether. A solution of 10 g. of N-methyl-N-nitrosotosylamide in 50 ml. of ether was placed in the dropping funnel.

Diazomethane was generated by warming the generation flask to 4045 C. and cautiously adding the N- methyl-N-nitrosotosylamide-ether from the dropping funnel. Nitrogen was utilized to sweep the diazomethane into a solution of 20 g. of 3a-acetoxy-l6-pregnene-11,20-dione in 100 ml. of tetrahydrofuran and ml. ether. The process was continued until the steroid solution remained yellow for several hours. The product, 3a-ECCtOXY-16ot, 17u-methyleneazo-pregnane-11,2D-dione largely precipitated from the reaction mixture. After 16 hours, the mixture was filtered, washed with ether and dried in air.-Yield 14.24 g., M.P. l86l90 C. (dec.) 2nd crop (on concentration) 4.45 g., M.P. 18-0-187 0., 3rd crop, 1.32 g., M.P. 180-190 C. Total usable material 20.01 g. (90%).

1.11. iggf 5.78 sh, 5.82, 6.39,.

will? Analysis.-Calculated for C H O N C, 69.55; H, 8.27. Found: C, 69.37; H, 8.01.

EXAMPLE 2 Preparation of 3ot-acetoxy-16-methyl-16-pregnene-1L20- dz'one; 3u-acetoxy-1 6 12,1 7a-methylenepregnane-1 1,20- dione; 3a-acet0xy-1 6-methylenepregnan'e-1 1 ,ZO-dione and 3a-hydr0xy-16-methyl-1 6-pregn'ene-1 1,20-dz'0ne and was taken up in about ml. of acetone, filtered m1. and ether slowly added to the boiling solution until crystallization occurred. These crystals of 3otacetoxy-16- methyl-l6-pregnene-l1,20-dione weighed 19.0 g., M.P. 1-65-168 C.;

2nd crop 5.3 g., M.P. -164 C.,

3rd crop 5.0 g., M.P. 142153 C.,

max. 1113K.

Analysis.Calculated for C H O C, 74.57; H, 8.87. Found: C, 74.30; H, 8.60.

The mother liquors obtained above contained additional 3ot-acetoXy-16-methyl-16-pregnene-11,20-dione as Well as the corresponding isomeric cyclopropane, 3u-acetoXy-16u,17u-methylenepregnane-11,20-dione, M.P. 166- 1 1 enepregnane-11,20-dione which were isolated by chromatography.

The latter, Zia-acetoxy-16-methylenepregnane-11,20-dione, was transformed to 3a-hydroxy-16-methyl-l6-pregnene-l1,20-dione by methanolic potassium hydroxide.

EXAMPLE 3 Preparation of 16ot,l 7OL-EPOXY-30t-hydl'OXy-16 8-m8thylpregnane-I 1 ,2 O-dione A solution of 20.0 g. of 30a acetoxy 16 methyl-16- pregnene-11,20-dione dissolved in 600 ml. of methanol, was cooled to 18 C., and 80 ml. of 30% hydrogen peroxide followed by 80 ml. of 2.5 N sodium hydroxide were added. Considerable material precipitated from solution, but all redissolved on stirring the reaction mixture at 25-30" C. for 40 minutes. The solution was kept at 15 20 C. for 18 hours at which time the ultra-violet maximum at 249 had completely disappeared. Then 600 ml. of saturated salt water was slowly added, the crystalline precipitate was filtered, washed with water, and dried in air and in vacuum. The 1604,1712 epoxy 3a hydroxy 16,8 methylpregnane 11,20 dione thus formed weighed'17.36 g. (93%); M.P. 176-177 C., hexagonal prisms M.P. 178180 C. from acetone-ether.

:Found: c, 71.65; H, 8.25.

EXAMPLE 4 Preparation of an olefin mixture of 3a,]7a dihydroxy- 16 methyl 15 pregnene 11,20 dione and 3a, 1 7-dihydr0xy-1 6-methylenepregnane-11,ZO-diOn'e To a solution of 2.69 g. of 16ot,l7a epoxy 3a hydroxy 16,8 methyl-pregnane 11,20 dione in 55 ml. dioxane was added 27 ml. of 2 M aqueous perchloric acid. The clear solution was kept at 2530 C. for 65 hours. Cold water, (175 ml.) was added, the slurry chilled to 8 C. and filtered after 30 minutes. The precipitate, containing a mixture of 3a,17 x dihydroxy 16 methyl-15- pregnene 11,20 dione and 312,1712 dihydroxy 16- methylene-pregnane was washed with water, and dried in air and finally at 50 C. in vacuum. Yield: 2.27 g. (94.5% M.P. sintering at about 150 C. melting at 158167 C. The relative proportion of 3u,17a-dihy- 'droxy 16 methyl 15 pregnene 11,20 dione and 3a,17a dihydroxy 16 methylenepregnane 11,20-dione is estimated to be of the order of 1:1.

EXAMPLE 5 Preparation of 312,115 dihydroxy l6 methyl 15- etiocholene l7 one and 3a,11{3 dihydroxy 16- methyl eneetiocholane-l 7 -one The conjugate C=O peaks at 5.80 and 5.87 were of equal intensity indicating the proportions to be 1:1.

12 Pure 3a,11,8 dihydroxy 16 methyleneetiocholane- 17-0ne EXAMPLE 6 Preparation of 3a acetoxy 17a-hydr0xy-16-methylenepregnane-J 1,20-di0ne and 3 -acet0xy-25-bromo-1 6-methyl-l -pregnene-11,20-di0ne To stirred solution of 5.05 g. of 3a acetoxy 16a,l7 xepoxy 16B methylpregnane 11,20-dione in 75 ml. of acetic acid maintained at 1015 C. was added 25 ml. of cold 15% hydrogen bromide in acetic acid. After 35 minutes at 10-15 C. the mixture was concentrated to dryness in vacuo (temperature 15 C.) and the residue chromatographed on 200 g. of neutral alumina. From the 60:40 petroleum ether-benzene eluates there was obtained 2.10 g. of 34x acetoxy 15oz bromo 16 methyl-16- pregnene 11,20 dione; rectangular prisms from etheracetone M.P. l30-135 C.dec.

]gHC1a+ o CHaOH IBEX.

250 u E=9.0o0;

g =52 0:1.00 my 2.95, 5.75, 5.82, 5.87

Analysis.-Calculated for C H O C, 71.61; H, 8.51. Found: C, 71.51; H, 8.07.

EXAMPLE 7 Preparation of 30 acetoxy 16 methyl 14,16- pregnadiene-I 1 ,ZO-dione 42 mg. of 30a acetoxy 15a bromo 16 methyl- 16 pregnene 11,20 dione was dissolved in 2 ml. of pyridine. After 18 hours at 25 C. the mixture was concentrated to dryness in vacuo. The solid residue of 306- acetoxy 16 methyl 14,16 pregnadiene 11,20-dione was crystallized from ether; prismatic needles M.P. C.

301 In E: 11,000

EXAMPLE 8 A solution of 3.05 g. (8.47 millimol) of the olefin mixture of 312,170: dihydroxy 16 methyl 15 pregnene- 11,20 dione and 3:2,1712 dihydroxy-16-methylenepregnane 11,20 dione in 80 ml. of methanol was reduced in hydrogen at 1 atmosphere and 25 C. in the presence of 2.0 g. of 25% palladium-calcium carbonate catalyst. Modification of the hydrogenation conditions, pH, solvent, catalyst, etc. alters the isome-r ratio significantly. Uptake of the calculated amount of hydrogen was complete in 45 minutes. The mixture was stirred an additional 30 minutes and filtered through diatomaceous earth. The colorless filtrate was taken to dryness and crystallized from ether: a mixture of 301,170 dihydroxy 160a methylpregnane 11,20 dione and 3a,17a dihydroxy 16,6-

methylpregnane 11,20 dione was obtained and weighed 3.05 g., sintering at 150 C. melting at 166-182 C.

xCHCh 2.79, 2.95, 5.87

max.

The product consists of 3u,17a dihydroxy 16oz methylpregnane 11,20 dione and 3a,17a dihydroxy 16(3- methylpregnane 11,20 dione in the ratio ca. 7:3 as determined by the amounts of end product isolated below.

EXAMPLE 9' Alternate preparation of 3a,]7a-dihydroxy-1(ix-methylpregnane 11,20 dione and 30:,170: dihydroxy 16,8- methy Ipregnane-l 1,20-dione A solution of 10.0 g. of 1604,17u epoxy 30L- hydroxy- 16/3 methylpregnane 11,20 dione in 180 ml. of dioxane and 112 ml. of 2M aqueous perchloric acid was prepared. The solution was hydrogenated at 25 C. and 1 atmosphere pressure in the presence of 4.4 g. of 5% palladium on charcoal catalyst. Uptake of one mole of hydrogen was complete in 10 hours. The catalyst was removed by filtration and 300 ml. of 70% saturated sodium chloride was added to the filtrate. After being kept at C. for 30 minutes, the precipitated mixture of 3a,17a-dihydroxy- 16oz methylpregnane 11,20 dione and 3a,l7a di hydroxy 16B methylpregnane 11,20 dione was filtered, washed with water and dried in air. Yield: 9.26 g. Solubility analysis in benzene indicated the product to be 75% 3u,17a dihydroxy -16a methylpregnane 11,20- dione and 25% 3a,17ot dihydroxy 16B methylpregnane 11,20 dione.

EXAMPLE 10 Separation of 3a,]7oc dihydroxy 16a methylpregnane- 11,20 dione and 3a,17a-dihydroxy 165 methylpretgnone-11 ,ZO-dione Analysis.Calculated for C H O C, 72.89; H, 9.45. Found: C, 72.97; H, 9.25.

The 16a-methyl and l6 3-methylpregnanes respectively, had R values of 0.55 and 0.35 when chromatographed on Whatman #1 filter paper in the benzene-formamide systern.

As described hereinafter, 3a,17a dihydroxy 16B- methylpregnane-l1,20-dione was brominated at position 21 in exactly the same way as the mixture of 160a and 165- methyl compounds to give 21 bromo 304,170: di-

hydroxy 16;? methylpregnane 11,20 dione. This latter compound was similarly converted to 30c,17ot,2l-dihydroxy 16p methylpregnane 11,20 dione 21- acetate. This compound was then similarly oxidized at position 3 to give 17 x,2l dihydroxy -16,8 methyl 3, 11,20 trione 21 -acetate.

EXAMPLE 1 1 Preparation of a mixture of 3a-acetoxy-17a-hydr0xy-16amethyl pregnane 11,20 dione and 3a acetoxy 170chydroxy-16,8-methyIpregnane-Z 1,20-dione To a mixture of 3a,17a dihydroxy 16a methylpregnane 11,20 dione and 3a,17a dihydroxy 16/3 methylpregnane 11,20 dione dissolved in pyridine was added acetic anhydride at 20 C. A mixture of 3u-acetoxy-l7ahydroxy 16a methylpregnane 11,20 dione and 3aacetoxy 170a hydroxy 16,3 methylpregnane 11,20- dione separated from solution and was recovered. These prisms sintered at 170 C. and melted at 175179 C.

EXAMPLE 12 Preparation of a mixture of 21 -bromo-3a-1 7a-a'ihydr0xy- 16a methylpregnane 11,20 dione and 21 bromo- 3 00,1 7a-dihydroxy-16/i-methylpregnane-11,ZO-dione A solution of 3.50 g. (9.7 millimol) of a mixture of 30:, 17a dihydroxy 160: methylpregnane 11,20 -dione and 3a,17a dihydroxy 16emethylpregnane 11,20- dione obtained as above in 40 ml. of chloroform was warmed to 40-45 C. A solution of 1.76 g. (11 millimol) of bromine in 25 ml. of chloroform was added dropwise to the stirred solution such that the color was not darker than pale yellow (ca. 2 drops/sec, total time-4 hour). The nearly colorless solution was cooled to 20 C. and 200 ml. of ether was added. The mixture was extracted with excess cold 5% potassium bicarbonate solution, sodium bisulfite solution, and water and dried over magnesium sulfate. The colorless residue after removal of solvent, a mixture of 21 bromo 3a,17a dihydroxy 160cmethylpregnane 11,20 dione and 21 bromo- 3a,17e-

EXAMPLE 13 Preparation of a mixture of 3a,1'7a-21-trihydr0xy-1 6 amethylpregnane-11,20-dione 21 -acetate and 3 u,17ot,21- trihydroxy-l 6B-methylpregnane-11,20-dione 21 acetate To 4.30 g. of 21-bromo-3a,l7a-dihydroxy-l6a-methyl- 'pregnane 11,20 dione and 21 bromo 3a,17a dihydroxy 16 3 methylpregnane 11,20 dione in ml. of acetone and 0.10 ml. of acetic acid were added 4.83 g. of anhydrous potassium acetate and 3.85 g. of potassium iodide. The stirred mixture was refluxed for 18 hours and concentrated on the water pump to a small volume. Water was added, the product extracted into ethyl acetate, and the organic extract dried over magnesium sulfate. The product (4.25 g.) was a colorless foam that partly crystallized from acetone-ether to give ca. 30% dense cubes sintering at about 150 C.,and melting at ZOO-213 C., which paper chromatography showed was mainly 3a,17a, 21 trihydroxy --16[3 methylpregnane 11,20 dione 21- acetate contaminated with some 3a,17u,21 trihydroxy- 16cc -methylpregnane 11,20 -dione 21 acetate. The IR. spectrum of this material was similar to that of authentic 3a,17a,21 trihydroxy 16cc methylpregnane 11,20- dione 21 acetate in the functional group region but differed significantly in the fingerprint region. Seedling the mother liquors with authentic 3a,17a,21-trihydroxy-16umethylpregnane-l1,20-dione 21-acetate induced crystallization of crude 3e,17w21-trihydroxy-16u-methylpregnane-11,20,-dione 21-acetate which was purified by repeated crystallization from acetone-ether and shown to be identical with an authentic sample by mixed M.P., LR. and paper chromatographic comparisons.

EXAMPLE 14 Preparation of 17u,21 dihydroxy-16a methylpregnanemethyl pregnane-3,1 1 ,ZO-trione 21 acetate To the mixture obtained as above of 3a,17oc,2ltrihy droxy 16cc methylpregnane-l1,20=dione 2l-acetate and 3a,17a,21 tr-ihydroxy 16-B-methylpregnane-11,20-dione '21acetate, 4.0 g., in ml. t-butanol and 20 ml. of water precipitate had formed; water was added, the precipitate filtered and washed with water: 3.30 g., sintering at about 170 C. melting at about 202212 C. Extraction of the filtrate with ethyl acetate gave .350 g., M.P. 130l70 C. Since both samples were mixtures by paper chromatography, they were recombined for alumina chromatography. Tritur-ation with 100 ml. hot benzene gave 540 mg. of material M.P. 225 235 C. Chromatography of the remainder on neutral alumina (85 g., 100 m1. fractions) gave 1.324 g. of 17a,21-dihydroxy-16a-methylpregnane-3,11,20-trione 21-acetate, M.P. 230 C. from fractions 5-15; (5% CHCl 70% C H Fractions 1721 (50% CHCl 50% C H to 100% CHCl contained 0.850 g. 17a,2l-dihydroxy-16B-methylpregnane-3,11,-20- trione 21-acetate, M.P. 210-213 C. The yield was about 2.0 g. [1.87 g.+ca. .10.20 g. in mixed fraction 16]. The ratio of 17oc,21 dihydroxy-l6a-methylpregnane-3,11,20- trione 21 acetate to 17a,21-dihydroxy-16B-methylpregname-3,11,20-trione 21-acetate, 2.0; 0.85:7:3, is probably close to the ratio of 3a,17a-dihydroxy-16a-methylpregnane-11,20-dione produced in the hydrogenation.

Pure 17a,21 dihydroxy-l6,B-methylpregnane-3,11,20- trione 21-acetate had the following properties: M.P. 210212 C.

Analysis.Calculated for C H O C, 68.88; H, 8.19. Found: C, 68.81; H, 7.91.

EXAMPLE 15 Preparation of 4 bromo-I711,21-dihydrxy-16B-methy lpregnane-3,11,20-tri0ne 21-acetate To a stirred solution of 585 mg. of 17u,2l-dihydroxy- 16B-methylpregnane-3,11,20-trione 21-acetate in 10 ml. of acetic acid and 8 ml. of chloroform kept at -10 C. was added slowly 230 mg. of bromine in. 6 ml. of chloroform. After addition was complete, 1.2 g. of sodium acetate in 7 ml. of cold water was added. Additional water was added and the mixture was extracted with chloroform. The chloroform extract was washed with dilute potassium bicarbonate, water and dried over sodium sulfate. The residue was triturated with ether to give 480 mg. of crystalline 4-bromo-l7a,21-dihydroxy-IGfi-methylpregnane-3,11,20-trione 21-acetate M.P. 1 65-1170 C. dec.

Analysis.-Calculated for C 4H O Br: =Br, 16.08. Found: Br, 15.58.

A second crop of 133 mg. of 4-bromo-17a,21-dihydroxy-16,8-methylpregnane-3,11,20-trione 21-acetate was also obtained.

EXAMPLE 16 Preparation of the 3-semicarbaz0ne of 17a,21-dihydr0xy- 16B-m-ethyl-4-pregnene-3,11,20-tri0ne 21-acetate To 583 mg. of 4-bromo-17a,2l-dihydroxy-l6B-methylpregnane-3,11,20-trione 21-acetate in 20 ml. of acetonitrile under nitrogen was added a slurry of 600 mg. of semicarbazide hydrochloride and 410 mg. sodium bicarbonate in 4 ml. of water. After 2 hours, the acetonitrile was removed in vacuo, Water added and 540 mg. of crystalline 3 semicarbazone of 1704,21-dihYdIOXY-l6fimethyl 4 pregnene-3,11,20-trione 21-acetate filtered, washed with water and dried.

EXAMP'LE 17 Preparation of 1 7a,21-dihydr0xy-16f3-methyl-4-pregnene- 3,11,20-tri0ne 21 -acetate 540 mg. of the semicarbazone of 17a,21-dihyd-roxy- 16fl-methy1-4-pregnene-3,11,20-trione 21-acetate was dissolved in -20 m1. of acetic acid, 1.5 ml. of pyruvic acid and ml. of water. After 18 hours at 25 C., water was added and the mixture extracted with chloroform. The chloroform extract was washed with aqueous potassium bicarbonate, water and dried over sodium sulfate. Removal of solvent gave crude l7a,2l-dihydroxy-16fl- 16 methyl 4-pregnene-3,11,20-trione 21-acetate which was purified by chromatography on neutral alumina and crystallization from acetone-ether (hexagonal plates). The pure material had M.P. 226232 C. xfifigf 238 m E=15,600; xCHG13 2.85-2.98, 5.73, 5.79,

Analysis.-Calculated for C H O C, 69.21; H, 7.75. Found: C, 69.24; H, 7.53.

EXAMPLE 18 Preparation of the 3,20-disemiearbaz0ne 0 1 7a,21-dihydroxy-l 6,8411ethyl-4-pregnene3,11,20-tri0'ne 21 acetate To a stirred solution of 500 mg. of 17a,21-dihydroxy- 16,8 methyl 4-pregene3,11,20-trione 21-acetate (prepared as described in Example 17) in 12.5 ml. of methanol and 3 ml. of dimethylformamide kept under nitrogen was added a slurry of 680 mg. of semicarbazide hydrochloride and 370 mg. of sodium bicarbonate in 1 ml. of water. The stirred mixture was refluxed 3 /2 hours and maintained at 45 C. for 17 hours. It was then cooled to 20 C. and 50 ml. of 50% saturated aqueous sodium chloride was added. After 2 hours at 0 C. the precipitate of the 3,204iisemicarbazidone of 17a,21-dihydroxy-l6[3- methyl-4-pregnene-3,11,20-trione 21-acetate was filtered, washed with water until free of chloride ion and dried in air. Yield over 7 EXAMPLE 19 Preparation of the 3,20-disemicarbaz0ne 0f 115,121,21- trihydrOxy-J 6fi-methyl-4-pregnene-3,20-dione To a stirred solution of 600 mg. of the 3,20-disemicarbazone of 17a,21-dihydroxy-16B-methyl-4-pregnene-3,11,- ZO-trione 21-acetate in 30 ml. of tetrahycl-rofuran and 11 ml. of water under nitrogen was added 200 mg. powdered sodium borohydride. The stirred suspension was refluxed 45 minutes and then cooled to 15 C. Aqueous acetic acid (3 ml. of 30% was added cautiously and most of the tetrahydrofuran was removed in vacuum. Addition of 5 ml. of methanol and 5 ml. of water induced the product to crystallize. Following addition of 10 ml. of a saturated sodium chloride solution and aging at 0 C. the product 3,20 disemicarbazone of 1l,8,l7a,21 trihydroxy-16fimethyl-4-pregnene-3,20-dione was filtered, washed with water, and dried in air.

EXAMPLE 20 Preparation 0 115,1 7a,21-trihydr0xy-1 6B-methyl-4- pregnene-3,20-di0ne To a solution of 150 mg. of reduced 3,20-disemicarbazone of 1 1,8, l7a,21-trihydroxy-16f3-methyl-4-pregnene- 3,20-dione in 5 ml. of acetic acid was added 1.20 ml. of water and 0.50 ml. of p-yruvic acid. The solution was kept at 25 C. for eighteen hours. Water (20 ml.) was added, and the mixture was extracted thoroughly with chloroform. The chloroform extract was dried over magnesium sulfate and taken to dryness. The residue was crystallized from acetone-ether to give pure 11B,l7a,21 trihydroxy-16,8-methyl-4-pregnene-3,20-dione.

EXAMPLE 21 Preparation of 115,] 7a,Z1-trihya'r0xy-l 6B-methyl-4- pregnene-3,20-di0ne 21-acetate The product of the previous Example 2 0 was acetylaied at C21 as follows: A solution of mg. of 116,17a, 2l-trihydroxyl6fi-methyl-4-pregnene-3.20-dione in 1.0 ml. of pyridine and 0.5 ml. of acetic anhydride was prepared. After 18 hours at 25 C., the solution was taken to dryness in vacuo and the solid residue purified by crystallization in acetone-ether to give 11p,17a,21-trihydroxy-16pmet-hyl-4-pregnene-3,ZO-dione 21-acetate.

1 7 EXAMPLE 22 Preparation of 1 711,21 dihydroxy-1 6/3-methyl-4,9 (11 pregnadiene-3,20-dione 21 -acetate Crystallization of material eluted by benzene gave pure 17u,2 l-dihydroxy- 1 6,B-methyl-4,9 1 1 -pregnadiene 3,20- dione 21-acetate.

' EXAMPLE 23 Preparation of 9a-br0mo-J 1 8,] 70,21-tiillyd10X3I-16B- methyl-4-pregnene-3,20-dione 21 -acetate To a mixture of 620 mg. of 17u,21-dihydroxy-16flmethyl-4,9(11)-pregnadiene-3,20-dione 21 acetate and 330 mg. of N-bromosuccinimide in 10 ml. of dioxane and 3.2 ml. of water cooled to 10 C. was added 1.8 ml. of cold 1 M aqueous perchloric acid. The mixture was stirred at 15 C. for 3 hours. Excess N-bromosuccinimide was destroyed by addition of aqueous sodium thiosulfate and most of the dioxane was removed in vacuo. About 30 ml. of water was added and crystalline bromohydrin, 90cbromo-l1B,l7a,2l-trihydroxy-16 3-methyl 4 pregnene- 3,20-dione 21-acetate, was filtered, washed with water, and dried in air.

EXAMPLE 24 Preparation of 9fi,11fi-epoxy-17a,21-dihydr0xy-16,B- methyl-4-pregnene-3,20-dione 21 -acetate To a stirred solution of 100 mg. of the 9a-bromo- 11 8,17u,2l-trihydroxy-l6fi-methyl-4-pregnene-3,20 dione 21-acetate in 3 m1. of tetra-hydrofuran and 1 ml. of methanol under nitrogen was added 1.02 ml. of 0.215 N methanolic sodium methoxide. After 10 minutes at 25 C. 0.2 ml. of acetic acid was added and the methanol removed in vacuo. The residue was acetylated with 1.00 ml. of pyridine and 0.5 ml. of acetic anyhdride at 60 C. for 70 minutes. The mixture was taken to dryness in vacuo, water added, and product extracted into chloroform. The residue was crystallized from ether-acetone to give pure 9,8,11fi-epoxy17a,21 dihydroxy 16B methyl 4- pregnene-3,20-dione 21 acetate.

EXAMPLE 25 Preparation of 90t-fluOI'0-1 1 8,1 7u,21-trihydr0xy-16B- melhyl-4-pregnene-3,20-dione 21 -acetate To a solution of 200 mg. of 9B,ll,8-epoxy-17a,21- dihydroxy-16fi-methyl-4-pregnene-3,20-dione 21-acetate in 2 ml. of chloroform and 2 ml. of tetrahydrofuran in a polyethylene bottle at 60 C. was added 2 ml. of a 2:1 (by weight) mixture of anhydrous hydrogen fluoride and tetrahydrofuran. After 4 hours at l C. the mixture was cooled to '60 C. and cautiously added to a stirred mixture of 30 ml. of 25% aqueous potassium carbonate and 25 ml. of chloroform kept at C. The aqueous phase was further extracted with chloroform and the latter phase washed with water and dried over magnesium sulfate. The residue on crystallization from acetone-ether gave pure 9a-fiuoro-1118,17a,2l-trihydroxy-16,9-methyl-4- pregnene-3,20-dione-2l-acetate.

EXAMPLE 26 Preparation of Qa-fluoro-II /3,17ot,21-trihydr0xy-16{3- methyl-4-pregnene-3,20-dione To a stirred solution of 110 mg. of 9a-fluoro-11fl,17a,21- trihydroxy-16 3-methyl-4-pregnene-3,20-dione 21-acetate in 5 ml. of methanol under nitrogen at 25 C. was added 1.00 ml. of 0.26 M methanolic sodium methoxide. After 15 minutes 0.2 ml. of acetic acid in 1 ml. of water was added and the mixture concentrated nearly to dryness. The residue was taken up in ethyl acetate and the ethyl acetate solution was washed with water, dried over magnesium sulfate, and concentrated to dryness. Crystallizationof the residue from ethyl acetate, gave pure 9afluoro 11B,17a,21 trihydroxy 16B methyl-4-pregnene- 3,20-dione.

EXAMPLE 27 Preparation 0 f 9a-chl0ro-1 1 3-1 7a,21-trihydr0xy-16flmethyl-4-pregnene-3,20-a'ione 21 -acetate To a solution of mg. of 9B,11;8-epoxy-17a,21-dihydroxy-l6fl-methyl-4-pregnene-3,20-dione 21-acetate in 4 ml. of chloroform was added 5 ml. of concentrated hydrochloric acid. The twoaphase mixture was stirred at 25 C. for 1 hour. Addition of water and chloroform extraction gave a crude crystalline product which is partly deacetylated. Treatment with 1 ml. of pyridineand 0.5 ml. of acetic anhydride at 25 C. for 18 hours followed by concentration in vacuo and crystallization of the residue from acetone-ether afforded pure 9otCh10I0-1l}9,17oc,21 trihydroxy-16/3-methyl-4-pregnene-3,20-dione 21-acetate.

EXAMPLE 28 Preparation of 2,4-dibromo-1 7 0:,21 dihydroxy-1 6 3-. methyl-pregnane-3,1 1,20-trione 21 *acetate fite. The mixture was concentrated in vacuo to remove the chloroform and 20 ml. of water was added. The white powdery precipitate of 2,4.-dibromo-17a,21-d ihydroxy-16fi-methylpregnane-3,11,20-trione 21-acetate was filtered, washed with water and dried in air. Yield: 920 mg. M.P. 122130 C. dec.

EXAMPLE 29 Preparation 0 1 7 04,21 -dihydroxy-1 6B-methyl-1 ,4- pregnadiene-3,11,20-tri0ne 21 -acetate To a solution under nitrogen of 900 mg. of the 2,4- dibromo 170:,21 dihydroxy 16B methylpregnane- 3,11,20-trione 21-acetate in 5 ml. dimethyl formamide was added 200 mg. of sodium bromide. After 1 hour at 25 C., 1 ml. of dimethyl-aniline was added and the mixture maintained at C. for 2 /2 hours. The mixture was cooled, added dropwise to dilute hydrochloric acid, and solid, crude product filtered, washed with dilute hydrochloric acid, water and dried in air. Treatment with charcoal, followed by crystalliaztion from acetone gave 17a,21-dihydroxy-16fl-methyl-1,4 pregnadiene 3,11,20- trione 21-acetate M.P. 230-233 C.

igg 238 m (E 15,300) xg gg 2.93.0, 5.75, 5.79, 5.84, 6.01, 6.16, 6.19, 11.20 [a]g +2l6 (C=.805)

Analysis.-Calculated for C H O C, 69.55; H, 7.30.

' Found: 0, 69.25; H, 7.25.

EXAMPLE 30 Preparation of 1 70:,21-dihydroxy-16fl-methyl-L4- pregnadiene-3,1 1,20-trione Preparation of 1 1 8,1 7a,21-trihydr0xy-16fi-methyl-L4- pregnadiene-3,20-dione 21 -acetate To 100 mg. of 11;8,17a,21-trihydroxy-16B methyl 4- pregnene-3,20-dione 21-acetate in 5 ml. of t-butanol and 0.1ml. of acetic acid was added 50 mg. of selenium dioxide. The mixture was refluxed under nitrogen 18 hours, 50 mg. of selenium dioxide was added and the mixture refluxed an additional 24 hours. The mixture was filtered, and the filtrate taken to dryness. The residue was taken up in ethyl acetate and washed successively with aqueous sodium bicarbonate, ammonium sulfide, dilute ammonia water, water, dilute hydrochloric acid and water and dried over magnesium sulfate. It was then treated with activated charcoal and concentrated to dryness. Crystallization of the residue from acetone-ether gave pure 11p,17a,2l-trihydroxy-16/8-methy1-1,4-pregna diene-3,20-dione 21-acetate.

EXAMPLE 32 Alternately, the 1,2-dehydrogenation of 11;3,17a,21- trihydroxy-16a-methy1-4,-pregnene-3,20-dione 21 acetate can be carried out microbiologically by means of Bacillus sphaericus to yield 11,8,17a,2l-trihydroxy-l6/8-methyl-1,4- pregnadiene-3,20-dione, which on acetylation with acetic anhydride-pyridine gives 11/3,17a,2l trihydroxy 16(3- methyl-l,4-pregnadiene-3,20-dione 21-acetate.

EXAMPLE 33 Preparation of 9a-flu0r0-11/3,17a,21-trihydr0xy-16flmethyl-1,4-pregnadiene-3,20-dione 21 -acetate In a similar manner, 100 mg. of 9a-fluoro-11B,17a,21- trihydroxy-l6,8-methyl-4-pregnene-3,20-dione 21 acetate 20 was treated with selenium dioxide to produce the corresponding 9a-fluoro-11B,17u,21-trihydroxy-165 methyl 1,4-pregnadiene-3,20-dione ZI-acetate. Alternately, Bacillus sphaericus may be utilized. The 21-alcohol was prepared from the 21-acetate as in Example 26 or Example 30..

Various changes and modifications may be made in the present invention, certain preferred embodiments of which are herein disclosed, without departing from the scope thereof; to the extent that these changes and modifications are Within the scope of the appended claims, they are to be considered a part of this invention.

We claim:

1. The process which comprises reacting 3oc-10We1' alkanoyloxy-l6-lower alkyl-16-pregnene-11,20-dione with a peroxidic oxidizing agent to produce 16,8-lower alkyl- 16a,17a-epoxy-3a-hydroxypregnane-l1,20-dione, and reacting the lat-ter compound with hydrogen to form 16;?- lower alkyl-3 a,17a-dihydroxy-pregnane-1 1,20-dione.

2. The process which comprises reacting 16,8-lower alkyl-16a,17u-epoxy-3a-hydroxypregnane 11,20 dione with hydrogen under acidic conditions to form a mixture of 16u-lower alkyl-3a,17a dihydroxypregnane 11,20- dione and 16B-1ower alkyl 3a,17a dihydroxypregnane- 11,20-dione.

References Cited UNITED STATES PATENTS 2,705,233 3/1955 Julian 260239.55

FOREIGN PATENTS 744,237 2/ 1956 Great Britain.

OTHER REFERENCES Julian et al., J.A.C.S. (1955) vol. 77, pp. 4601-4604 relied upon. Copy in Scientific Library.

Boland, California Practice (1958) vol. 88, pp. 417- 420.

ELBERT L. ROBERTS, Primary Examiner. 

1. THE PROCESS WHICH COMPRISES REACTING 3A-LOWER ALKANOYLOXY-16-LOWER ALKYL-16-PREGENE-11,20-DIONE WITH A PEROXIDIC OXIDIZING AGENT TO PRODUCE 16B-LOWER ALKYL16A, 17 A-EPOXY-3A-HYDROXYPREGNANE-11,20-DIONE, AND REACTING THE LATTER COMPOUND WITH HYDROGEN TO FORM 16BLOWER ALKYL-3A, 17 A-DIHYDROXY-PREGNANE-11,20-DIONE. 